Blocking a request if the URL meets two parameter requirements?

I have a API request that has two parameters that can easily be tampered. The problem is that there are legitimate requests that will match the numbers if I only have a parameter rule on one of the values and not the other. So I need a way to have the equivalent of a "AND" statement saying if VariableA=x and VariableB=y to block the request. But if VA=x and VB= to not block anything. Is this a possibility in the standard settings for ASM parameters or will this require some type of iRule. Thank you!